We have to prove that \((1+\cosθ)(1−\cosθ)=\sin^2θ\)

Let us start from left hand side. By using the identity \(a^2−b^2=(a+b)(a−b)\) we get \((1+\cosθ)(1−\cosθ)=1−\cos^2(θ) =\sin^2θ\)

asked 2021-06-27

Prove that \((1+\cos\theta)(1−\cos\theta)=(\sin^2)\theta\)

asked 2020-11-07

asked 2021-05-08

asked 2021-08-21

asked 2021-05-22

Given that \(\cos\theta = -0.489\) where \(\pi<\theta<3\frac{\pi}{2}\), find \(\sin\theta\)

asked 2020-12-27

asked 2020-11-22

a. What two triangles must be congruent to prove \(\overline{HB}\cong \overline{HE}\)?

b. Write a proof to show \(\overline{HB}\cong \overline{HE}\)